Patent GB-944469-A (GB)
Title: Apparatus for crimping electrical connectors to electrical conductors
IPC: H01R43/048
Filed: 1962-09-25
Abstract: 944,469. Making electrical connections; printing by stamping; shearing. AMP Inc. Sept. 25, 1962 [Oct. 2, 1961], No. 36356/62. Headings B3A, B3Q and B3W. Apparatus for crimping an electrical connector to an electrical conductor, comprises a first reciprocable ram carrying a die for crimping the connector to the conductor in cooperation with a fixed crimping anvil, means on the ram for coupling it to a second ram and an adjustable member having thereon a series of projections selectively interposable between the two rams, to transmit motion from the second ram to the first ram, the projections being differently dimensioned so that the stroke of the first ram can be adjusted in steps. The crimping unit 2 is mounted on a conventional bench press 1 having a reciprocal press ram 3 drivable through a single cycle, a feed spool 8, a resilient guide 9 and an intermittent feed arrangement (not shown). A strip comprises a series of U-shaped connectors comprising first and second portions for crimping to the wire and insulation respectively, a contact portion and a slug portion which connects adjacent connectors to each other. The unit 2 comprises a split housing 10, 11, the part 10 having a verticle recess 14 which houses a ram 15 to which are attached crimping dies 26, 27, below which is arranged a crimping anvil 21 having recesses 22, 23 for supporting the connector which co-operate with working surfaces 34, 33 of the dies. The dies 26, 27 separated by a plate 28 are attached to the ram 15 by a screw 29 which passes through a clearance slot in the die 27 and fitted slots in the plates 28 and die 26. The die 27 is slidable against the plate 28 to which it is frictionally held by a washer 32 fitted under the head of the bolt 29. The upper ends of the dies 26, 27 abuts a shoulder 36 of the ram 15 and a block 37 slidably fixed to the ram by a screw 38 respectively. A headed spindle 41 pinned at 44 to the ram 15 is coupled by its head 42 to a recess bounded by a pair of opposed claws 52 on the ram 3. A space plate 45 and a pair of rotatably mounted dials 46, 47 for adjusting the stroke of the dies 27, 26 are mounted on the spindle, each dial being set relative to the spindle by the engagement of a spring detent contained therein with grooves formed around the spindle diameter. Pairs of upstanding projections 48 to 51 each pair being of equal height but the different pairs being of unequal height are formed on the top face of the dial 47 which abuts the lower face of the claws 52. The dial 46 of a larger diameter has similar projections on its underside which engage the block 37. A series of axial holes 55 extending through one of the projections of the discs are engaged by a spring detent pin 56 mounted in a block 58 secured to the ram 15 to retain the dials in their set conditions. The pin 56 can be depressed for resetting. The ram 3 is adjustably connected to the press linkage via a ball-andsocket assembly. A strip feed mechanism comprises a plate 68 extending transversely of the ram 15 to which is fixed a plate 69 to provide a channel 70, a block 71 secured to the plate 69 and slidably adjustable via a nut-and-screw 73 assembly along a base 72 of the apparatus and rear and forward shear blocks 77, 78 fixed to the block 71 and having notches 80, 81 through which the strip is fed. A movable shear blade 84 is attached to a pair of rods 83 slidable in parallel channels 82 in the block 77 the projecting ends 86 of which are slidable along the arms of a T-shaped extension 87 on the lower end of the ram 15. A feed finger carrier 88 biased in a clockwise direction by a spring 93 and having a bifurcated feed finger 91 is rotatably mounted beneath the plate 69 on a rod 89 carried by a slide 90 engaging the plates 68, 69. The finger extends through an opening 92 in the plate 69 to engage the strip 7. The slide 90 is normally biased in the direction of the anvil by springs 94 through which extends tubes 95 fixed at one end to the slide and at the other to a cross-bar 96 on the plate 68. A rod 97 axially slidable in one of the tubes is retainable in a given position to the tube by a bayonet joint 98. A feed stop 99 biased in an anticlockwise direction by a spring 101 is rotatable about a pin 100 pivoted on a plate 103 attached to the plate 68 to allow the strip to be fed to the anvil. A cam 105 attached to the end of the rod engages an extension 104 of the stop 99 to disengage the stop from the strip. A bracket 106 prevents the strip being lifted by the shear blade 84. A cam surface 107 of the block 58 engages a roller 108 mounted between two arms of a link 109 pivoted to a housing 110 by a pin 111. The upper end of the link 109 bears against a lever 112 having a bifurcated lower end pivoted to a central rib 113 in the housing 110. The lever 112 bears against a pin 114 between the arms of a link 115 pivoted to the housing 110 a block 116 extending from the upper end of the link 115 and rotatably receiving a screwed rod 117 engaging a tapped extension of a block 118 carried by the pin 114. The block 118 is slidable along the link 115 by rotating the rod 117. A cam follower 119 at the lower end of the link 115 bears against the head of a bolt 120 on the slide 90 so that when the link is rotated by the ram 15 during its working stroke the siide 90 and the finger 91 is retracted, the slide being advanced during the return stroke of the ram 15 by the springs 94. The crimping apparatus is retained in position on the press by the tapered surface of a block 127 fitted to the plate 72 engaging a bar 128 extending through the press housing 4. The flats on a pin 121 protruding from the plate 72 engage the small cross-section end of a keyhole slot 122 in a plunger 123 spring-biased in a housing 124 to retain the apparatus in position. Retraction of the plunger 123 allows the pin 121 to be withdrawn through the larger section of the slot and the apparatus to be removed from the press. Operation.-The dials 46, 47 which adjust the stroke of the dies 27, 26 respectively are adjusted to suit the connector, insulation and wire sizes and the feed stroke adjusted by the screw 117 so that the stroke of the finger 91 slightly exceeds the connector length. The shear block 77 is adjusted by the screw 73. With the leading connector of the strip positioned on the anvil 21 and the ram raised the bared end of an insulated wire is inserted into the unit until it abuts a stop 35 and the press is energized for one cycle. As the ram 15 descends the screw 120 via its cam and linkage retracts the slide 90 and causes the feed finger 91 to retract the strip to position the connector so that its insulation and wire ferrale forming portions lie in the recesses 23, 22 of the anvil and the slug connecting the connectors lies between the shear edges of the blocks 77, 78, the stop 99 abutting the leading connector portion to prevent further retraction. Continued downward movement of the ram retracts the slide 90 still further and causes the finger 91 to move downwardly out of engagement with the strip and the crimping operation to be carried out. The leading connector is sheared from the strip just prior to completion of the crimping. During the return stroke the springs 94 advance the feed finger to re-engage the strip and slightly over advance a connector length on to the anvil 21. Specification 944,470 is referred to.